KR101065975B1 - Mold release film - Google Patents

Abstract

An object of the present invention is to provide a release film that is excellent in flexibility at high temperatures, conformity to irregularities, heat resistance, mold release property, and non-pollution property, and is easy to discard after use. This invention is a release film used in the manufacturing process of a printed wiring board, a flexible printed wiring board, or a multilayer printed wiring board, Resin which has a resin which has a polar group in a principal chain on one or more surfaces as a matrix, and has a halogen content of 5 weight% or less. A release film having a layer comprising the composition.

Release film, printed wiring board, flexible printed wiring board, multilayer printed wiring board, halogen, polar group

Description

Release film {Mold release film}

The present invention relates to a release film that is excellent in flexibility at high temperatures, conformity to irregularities, heat resistance, mold release properties, and non-pollution properties, and is easy to discard after use.

In manufacturing processes, such as a printed wiring board, a flexible printed wiring board, and a multilayer printed wiring board, a release film is used when heat-compressing a copper clad laminated board or copper foil through a prepreg or a heat resistant film. In addition, in the manufacturing process of a flexible printed circuit board, when a coverlay film or a reinforcement board is thermocompression-bonded to the flexible printed circuit board body which formed the electric circuit by the thermosetting adhesive or the thermosetting adhesive sheet, a coverlay film and a compression hotplate In order to prevent this adhesion, the method of using a release film is widely performed.

As a release film used for these uses, a fluorine-type film, a silicone coating polyethylene terephthalate film, poly as disclosed by Unexamined-Japanese-Patent No. 2-175247 and 5-283862. Methylpentene films, polypropylene films and the like have been used.

In recent years, due to increasing demands on environmental issues and safety, these release films are required to be easy to be disposed of in addition to the heat-resisting resistance to heat compression molding and the release property to printed wiring boards and thermal compression plates. come. In addition, non-pollution to copper circuits has also been important for improving product yield during thermocompression molding.

However, the fluorine-based film conventionally used as a release film is excellent in heat resistance, mold releasability, and non-pollution, but has a problem that it is not only expensive but also difficult to burn in waste incineration after use, and generates toxic gas. In addition, the silicone-coated polyethylene terephthalate film and polymethylpentene film may cause contamination of printed wiring boards, particularly copper circuits, and impair quality due to migration of low molecular weight materials contained in silicon and constituents. In addition, the polypropylene film was poor in heat resistance and insufficient in releasability.

Further, Japanese Laid-Open Patent Publication No. 2003-313313 discloses one layer containing a resin composition containing 100 parts by weight of a resin containing at least one thermoplastic resin and / or a thermosetting resin, and 0.1 to 100 parts by weight of a layered silicate. The release film which has the above is described. This release film does not generate toxic gases like a fluorine-based film, does not cause contamination by migration of low molecular weight like a silicone coated polyethylene terephthalate film or a polymethylpentene film, and is excellent in heat resistance and mold release property. However, it is insufficient in terms of followability to unevenness, so that a complicated electric circuit is formed during thermal compression, and can sufficiently follow the printed wiring board, flexible printed wiring board, multilayer printed wiring board, and flexible printed circuit board having unevenness on the surface. There was a problem that there was no. In addition, since the low molecular weight substance which causes outgas adheres to layered silicate inevitably, there existed a problem that the outgas resulting from this low molecular weight substance generate | occur | produces a little and contaminates a board | substrate.

An object of the present invention is to provide a release film that is excellent in flexibility at high temperatures, conformity to unevenness, heat resistance, mold release property, and non-pollution property, and is easy to discard after use.

This invention is a release film used in the manufacturing process of a printed wiring board, a flexible printed wiring board, or a multilayer printed wiring board, The resin composition which has resin which has a polar group in a principal chain on one or more surfaces as a matrix, and content of halogen is 5 weight% or less. It is a release film which has a layer containing these.

It is preferable that resin which has the said polar group in a principal chain is crystalline aromatic polyester, and it is more preferable that the said crystalline aromatic polyester contains at least butylene terephthalate as a crystal component. At this time, the crystalline aromatic polyester preferably has a heat of fusion of 40 J / g or more. It is preferable that the crystalline aromatic polyester has a glass transition temperature of 0 ° C to 100 ° C.

It is preferable that the outgas generation amount at the time of heating at 170 degreeC for 10 minutes of the release film of this invention is 200 ppm or less.

This invention is explained in full detail below.

In addition, in this specification, a film means not only a film but a sheet.

The release film of this invention is a release film used at the manufacturing process of a printed wiring board, a flexible printed wiring board, or a multilayer printed wiring board. That is, in the manufacturing process of a printed wiring board, a flexible printed wiring board, or a multilayer printed wiring board, the mold release film of this invention heat-press-forms the copper clad laminated board or copper foil through a prepreg or a heat resistant film, for example. Can be used when In addition, the release film of this invention can be used, for example in the manufacturing process of a flexible printed circuit board, when bonding a coverlay film or a reinforcement board with a thermosetting adhesive or a thermosetting adhesive sheet by thermocompression molding.

The mold release film of this invention has a layer (referred to as a mold release layer) which consists of resin which has a polar group in a principal chain as a matrix, and contains the resin composition whose halogen content is 5 weight% or less.

Halogen content rate of the resin composition which comprises the said release layer is 5 weight% or less. The release film of the present invention having a release layer containing such a resin composition hardly generates harmful substances including halogen even when incinerated. Preferably it is 3 weight% or less, More preferably, it is 1 weight% or less. Less than 1% by weight is recognized as a substantial non-halogen material in Europe. In addition, the content rate of halogen can be measured by using a normal halogen analyzer.

The resin composition which comprises the said release layer uses resin which has a polar group in a principal chain as a matrix. By using such a resin as a matrix, the release film of the present invention can exhibit excellent mechanical performance, particularly excellent mechanical performance in a temperature range of about 170 ° C. which usually performs thermal compression.

Although it does not specifically limit as a polar group in resin which has the said polar group in a principal chain, For example, ester group, an amide group, an imide group, an ether group, a thioether group, a carbonyl group, a hydroxyl group, an amino group, a carboxyl group, etc. are mentioned.

It does not specifically limit as resin which has the said polar group in a principal chain, For example, a polyester compound, polyphenylene sulfide, a polyether ether ketone, a polyamide compound, a polyimide compound, etc. are mentioned. Resin which has these polar groups in a main chain may be used independently, or may use 2 or more types together. Among them, the crystalline aromatic polyesters described below are preferred because they do not contain heteroatoms in the molecule, and thus the environmental load during incineration is reduced and economically advantageous.

The crystalline aromatic polyester can be obtained by reacting an aromatic dicarboxylic acid or an ester-forming derivative thereof with a low molecular weight aliphatic diol. The crystalline aromatic polyester can also be obtained by reacting an aromatic dicarboxylic acid or an ester-forming derivative thereof with a low molecular weight diol and a high molecular weight diol (the crystalline aromatic polyester thus obtained is Crystalline aromatic polyesters having a polyether skeleton in the main chain). In addition, the crystalline aromatic polyester is obtained by dissolving a crystalline aromatic polyester obtained by reacting an aromatic dicarboxylic acid or an ester-forming derivative thereof with a low molecular weight aliphatic diol in a caprolactone monomer, followed by ring-opening polymerization of caprolactone. It can also be obtained (the crystalline aromatic polyester thus obtained is referred to as crystalline aromatic polyester having a polycaprolactone skeleton in the main chain hereinafter). Especially, the release film containing the crystalline aromatic polyester which has a polyether skeleton in a main chain, and / or the crystalline aromatic polyester which has a polycaprolactone skeleton in a main chain is an aromatic dicarboxylic acid or its ester formable derivative, Compared with the release film containing the crystalline aromatic polyester obtained by reacting a low molecular weight aliphatic diol, it becomes excellent in flexibility and mold release property, maintaining heat resistance.

Examples of the aromatic dicarboxylic acid or its ester-forming derivatives include terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, paraphenylenedicarboxylic acid, terephthalate dimethyl, isophthalic acid and dimethyl orthophthalate, Dimethyl naphthalenedicarboxylic acid, dimethyl paraphenylenedicarboxylic acid, etc. are mentioned. These may be used independently or may be used together 2 or more types.

Examples of the low molecular weight aliphatic diol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentylglycol, 1,5-pentanediol, 1, 6- hexanediol, 1, 4- cyclohexane dimethanol, etc. are mentioned. These may be used independently or may be used together 2 or more types.

As said high molecular weight diol, polyethyleneglycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol, etc. are mentioned, for example. These may be used independently or may be used together 2 or more types.

As a crystalline aromatic polyester containing the said component, For example, polyethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, terephthalic acid butanediol polytetramethylene glycol copolymer, A terephthalic-acid butanediol- polycaprolactone copolymer etc. are mentioned. These may be used independently or may be used together 2 or more types.

It is preferable that the said crystalline aromatic polyester contains at least butylene terephthalate as a crystal component. By including the butylene terephthalate component, the crystalline aromatic polyester is particularly excellent in non-pollution and crystallinity.

When the said crystalline aromatic polyester contains a butylene terephthalate component as a crystal component, it is preferable that the release film of this invention is 40 J / g or more of heat of crystal melting. If it is less than 40 J / g, the heat resistance which can endure thermocompression molding may not be expressed, the dimensional change rate in 170 degreeC also becomes large, and there exists a possibility of damaging a circuit pattern at the time of thermocompression molding. More preferably, it is 50 J / g or more. In order to improve crystallinity and make high crystal melting calories, an additive for promoting crystallization such as a crystal nucleating agent may be added to the resin composition, and when the release film of the present invention is produced, the cooling temperature at the time of melt molding is adjusted. It is preferable to set above the glass transition temperature of the said aromatic polyester, and it is more preferable to set to 70-150 degreeC. In addition, the said crystal melting heat can be measured by differential scanning calorimetry.

As said crystalline aromatic polyester, crystalline aromatic polyester which has a polyether frame | skeleton in the principal chain to crystalline aromatic polyester obtained by making aromatic dicarboxylic acid or its ester-forming derivative, and low molecular weight aliphatic diol react, and / or It is preferable that it is a mixed resin which mixed the crystalline aromatic polyester which has a polycaprolactone skeleton in a main chain. Such mixed resins contain a polyether skeleton and / or a polycaprolactone skeleton in the main chain in a matrix comprising a crystalline aromatic polyester that does not contain the polyether skeleton and / or the polycaprolactone skeleton in the main chain. By the fine dispersion of the aromatic polyester, excellent flexibility can be obtained while maintaining the heat resistance. The combination of the release film, heat resistance, and mold release property of this invention containing this mixed resin, and the traceability to the uneven shape on the board | substrate, such as a circuit pattern and a through hole, becomes very excellent.

As said crystalline aromatic polyester, it is preferable that glass transition temperature is 0-100 degreeC. When it exceeds 100 degreeC, the releasability required at the time of thermocompression molding falls, flexibility cannot be exhibited, and the trackability to the uneven shape on the board | substrate, such as a circuit pattern and a through hole, may fall, and it is less than 0 degreeC. While release property at the time of thermocompression molding falls, the handleability of a release film may fall. In addition, in this specification, glass transition temperature means the temperature which the maximum resulting from micro-brown movement appears among the maximums of the loss tangent (tan-delta) obtained by dynamic viscoelasticity measurement. The glass transition temperature can be measured by a conventionally known method using a viscoelastic spectrometer or the like.

It is preferable that the outgas generation amount at the time of heating at 170 degreeC for 10 minutes of the release film of this invention is 200 ppm or less. By having the release layer, the release film of the present invention not only satisfies the flexibility at high temperatures required for the release film, the conformity to unevenness, the heat resistance, the release property, and the like, but also minimizes the generation of outgas and thus has high non-pollution property. Can be realized. In addition, the said outgas generation amount can be measured by a conventionally well-known method, such as the dynamic head space method gas chromatography analysis.

The resin composition constituting the release layer may contain a stabilizer. It does not specifically limit as said stabilizer, For example, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t- butyl- 4-hydroxybenzyl) benzene, 3, 9-bis {2- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) -propionyloxy] -1,1-dimethylethyl} -2,4,8,10-tetraoxaspiro [5, 5] hindered phenolic antioxidants such as undecane; Tris (2,4-di-t-butylphenyl) phosphite, trilaurylphosphite, 2-t-butyl-α- (3-t-butyl-4-hydroxyphenyl) -p-cumenylbis ( p-nonylphenyl) phosphite, dimyristyl 3,3'- thiodipropionate, distearyl 3,3'- thiodipropionate, pentaerythryl tetrakis (3-laurylthiopropio And stabilizers such as ditridecyl 3,3-thiodipropionate.

The resin composition which comprises the said release layer may contain additives, such as a fiber, an inorganic filler, a flame retardant, a ultraviolet absorber, an antistatic agent, an inorganic substance, and a higher fatty acid salt, in the range which does not impair practicality.

It does not specifically limit as said fiber, For example, Inorganic fiber, such as glass fiber, carbon fiber, boron fiber, silicon carbide fiber, alumina fiber, amorphous fiber, silicone titanium carbonaceous fiber; Organic fibers, such as aramid fiber, etc. are mentioned.

It does not specifically limit as said inorganic filler, For example, calcium carbonate, titanium oxide, mica, talc, etc. are mentioned.

The flame retardant is not particularly limited, and examples thereof include hexabromocyclododecane, tris- (2,3-dichloropropyl) phosphate, pentapropophenyl allyl ether, and the like.

It does not specifically limit as said ultraviolet absorber, For example, pt-butylphenyl salicylate, 2-hydroxy-4- methoxy benzophenone, 2-hydroxy-4- methoxy-2'- carboxy benzophenone, 2 And 4,5-trihydroxybutyrophenone.

It does not specifically limit as said antistatic agent, For example, N, N-bis (hydroxyethyl) alkylamine, an alkyl allyl sulfonate, an alkyl sulfonate, etc. are mentioned.

As said inorganic substance, barium sulfate, alumina, a silicon oxide, etc. are mentioned, for example.

As said higher fatty acid salt, sodium stearate, barium stearate, sodium palmitate, etc. are mentioned, for example.

The release layer may be a single layer structure or a multilayer structure. In the case where the release layer has a multilayer structure, the crystalline aromatic polyester obtained by reacting an aromatic dicarboxylic acid or its ester-forming derivative with a low molecular weight aliphatic diol is used as a surface layer, and the crystalline aromatic has excellent flexibility at high temperatures. A resin composition excellent in interfacial adhesion with polyester, for example, amorphous polyethylene terephthalate such as terephthalic acid butanediol polytetramethylene glycol copolymer, polyethylene-1,4-cyclohexylenedimethylene terephthalate, polyamide-polytetramethylene By using a glycol copolymer or a styrene-based thermoplastic elastomer as a middle layer, flexibility can be provided while maintaining the release property during compression molding, and the balance between the release property and the followability to the uneven shape on the substrate, such as a circuit pattern or a through hole, can be achieved. A very good release film can be obtained.

In the case where the release layer has a two-layer structure, it is preferable that the storage modulus at 170 ° C of one layer is lower than the storage modulus at 170 ° C of the other layer. In the case where the release layer has a multilayer structure having three or more layers, it is preferable that the storage modulus at 170 ° C of at least one of the intermediate layers is lower than the storage modulus at 170 ° C of the surface layer. By taking such a structure, flexibility can be provided while maintaining mold release property at the time of compression molding, and it can be used as a release film which is excellent in the balance between the mold release property and the followability to the uneven shape on the board | substrate, such as a circuit pattern and a through hole.

It is preferable that the surface of the release layer has smoothness, but slip property, anti blocking property, etc. necessary for handleability may be imparted, and an embossed shape suitable for cross section or above is provided for the purpose of air leakage during thermocompression molding. May be

The release layer may be heat treated to improve heat resistance, mold release property, and dimensional stability. The heat treatment temperature is more effective if it is a temperature lower than melting | fusing point of the resin composition which comprises the said release layer, 170 degreeC or more is preferable, and 200 degreeC or more is more preferable. As another method of improving heat resistance, mold release property, and dimensional stability of the said release layer, the method of extending | stretching to the uniaxial or biaxial direction, the method of rubbing a surface with a solid, etc. are mentioned, for example.

The minimum with preferable thickness of the mold release layer of this invention is 5 micrometers, and an upper limit is 200 micrometers. If it is less than 5 µm, the strength may be insufficient. If it exceeds 200 µm, the thermal conductivity at the time of thermocompression molding may deteriorate. More preferable minimum is 10 micrometers, and an upper limit is 100 micrometers.

The release layer can be produced by a melt molding method. It does not specifically limit as said melt-molding method, For example, the film formation method of the conventionally well-known thermoplastic resin film, such as an air cooling or water cooling inflation extrusion method, a T-die extrusion method, etc. are mentioned. In addition, when the said release layer has a multilayered structure, it can manufacture by co-extrusion T-die method etc., for example.

The release layer can exhibit very excellent mechanical performance by including the above-described configuration. In other words, the release layer usually has a storage modulus of 20 to 200 MPa, a 100% elongation load of 49 to 490 mN / mm, a tensile elongation at break of 500% or more at 170 ° C., which is usually thermally compressed. The dimensional change rate at the time of pressurizing for 60 minutes by 3 MPa of loads is 1.5% or less. By exhibiting such a mechanical performance, the release film of this invention is very preferable as a release film used in the manufacturing process of a printed wiring board, a flexible printed wiring board, or a multilayer printed wiring board.

If the storage modulus at 170 ° C. is less than 20 MPa, heat resistance to withstand thermal compression molding may not be exhibited. If the storage elastic modulus at 170 ° C. is exceeded, the sheet may not be sufficiently deformed during thermal compression molding. Followability to the uneven shape on the substrate such as holes may be lowered, and uniform adhesion to the circuit pattern of the coverlay film in the flexible printed circuit board may be lowered, for example. The upper limit is more preferably 150 MPa, and even more preferably 100 MPa. In addition, the said storage elastic modulus can be measured by the dynamic viscoelasticity measurement normally performed, and can be measured by a viscoelastic spectrometer.

When the 100% elongation load at 170 ° C is less than 49 mN / mm, when used as a release film, heat resistance that can withstand thermal compression molding may not be expressed, and when it exceeds 490 mN / mm, thermal compression molding may be performed. Since it is not sufficiently deformed, the followability to the uneven shape on the substrate such as the circuit pattern and the through hole is lowered, and the uniform adhesion to the circuit pattern of the coverlay film on the flexible printed circuit board is lowered, for example. In addition, the said 100% elongation load is a load when the strain reaches 100% in a general tensile test, and it can measure it by the method according to JISK7127.

If the elongation at break at 170 ° C. is less than 500%, it may burst at the time of following the uneven shape on the substrate at the time of thermocompression molding, which may contaminate the substrate. More preferably, it is 800% or more. In addition, the breaking elongation in this invention can be measured by the method based on JISK7127.

When the dimensional change rate at the time of pressurizing for 60 minutes by the load 3MPa at 170 degreeC exceeds 1.5%, there exists a possibility that a circuit pattern may be damaged at the time of thermocompression molding. More preferably, it is 1.0% or less.

The release layer overlaps with the polyimide and / or metal foil and has a high release property with respect to the polyimide and / or metal foil when pressed at 170 ° C. for 3 minutes at 3 MPa. In addition, having the above releasability means that the peeling force generated between the polyimide and / or the metal foil and the sheet or the film after the pressing treatment is low, so that the polyimide and / or the metal foil, the sheet, or the film does not break when imprinted. Means that.

The release layer also exhibits very good mechanical performance even in the temperature range of about 23 ° C. That is, the release layer has a storage modulus of 1000 to 5000 MPa and a tear strength of 98 N / mm or more at 23 ° C. in which normal work is performed. By exhibiting such mechanical performance, the release film of this invention is very excellent in handleability, and is a release film used when carrying out thermocompression molding in the manufacturing process of a printed wiring board, a flexible printed wiring board, or a multilayer printed wiring board, or a flexible printed circuit board. It is very preferable as a release film used when adhering a coverlay film or a reinforcement board with a thermosetting adhesive or a thermosetting adhesive sheet by thermocompression molding in the manufacturing process.

If the storage modulus at 23 ° C. is less than 1000 MPa, the mechanical strength at room temperature is lowered. Therefore, the strength is insufficient in the sealing process after compression molding, and the handleability of the sheet or film at room temperature may be lowered. When exceeded, it has a bad influence on the followability to the uneven | corrugated shape at the time of compression molding.

When the tear strength at 23 ° C. is less than 98 N / mm, when used as a release film, the strength may be insufficient in the bonding process after compression molding, and resin adhesion to a circuit may occur. Resin adhesion to such a circuit will significantly impair electroconductivity, and the whole printed circuit board will become a defective product. In addition, the said tear strength can be measured by the method based on JISK7128C method (square tear method).

The release film of this invention may include only the said release layer, and may have a resin film layer other than the said release layer. The release film of the present invention in which the release layer is laminated on at least one surface of the resin film layer has a cushioning property and strength for uniformly applying pressure during thermal compression molding.

Although it does not specifically limit as resin which comprises the said resin film layer, In the point which is easy to dispose after use, For example, polyethylene resin, a polypropylene resin, ethylene-methyl methacrylate copolymer, ethylene-vinyl acetate copolymer, etc. Olefin resin is preferable. These may be used independently or may be used together 2 or more types. Moreover, in order to improve adhesiveness with the said release layer, you may contain modified polyolefins, such as an acid-modified polyolefin, glycidyl modified polyolefin, resin which comprises the said release layer, etc. Moreover, it is preferable that melting | fusing point of resin which comprises the said resin film layer is 50 degreeC-130 degreeC in order to suppress the seepage to the through-hole of a prepreg and a thermosetting adhesive, and to obtain uniform adhesiveness to a circuit pattern. Moreover, it is preferable that the complex viscosity rate in 170 degreeC of resin which comprises the said resin film layer is 100-10000 Pa.s in order to acquire uniform adhesiveness to a circuit pattern.

It is preferable that the softening temperature as a whole of the mold release film of this invention which has the said resin film layer is 40-120 degreeC. If it is in this range, the seepage of the prepreg and a thermosetting adhesive agent to the through-hole can be suppressed, and uniform adhesiveness to a circuit pattern can be obtained. In addition, the said softening temperature can be measured according to JISK7196.

It does not specifically limit as a method of manufacturing the release film of this invention which has the said resin film layer, For example, water-cooled or air-cooled coextrusion inflation method; A method of forming a film by a coextrusion T-die method; A method of laminating a resin composition constituting a resin film layer on the release layer prepared in advance by an extrusion lamination method; The method of dry laminating | stacking the said release layer and resin film layer etc. which were previously prepared separately is mentioned. Especially, the film forming method by the co-extrusion T-die method is preferable at the point which is excellent in the thickness control of each layer.

Since the release film of this invention is excellent in flexibility, heat resistance, mold release property, and non-contamination property at high temperature, and can be discarded safely and easily, the release film used in the manufacturing process of a printed wiring board, a flexible printed wiring board, or a multilayer printed wiring board. Very preferred. That is, in the manufacturing process of a printed wiring board, a flexible printed wiring board, or a multilayer printed wiring board, the release film of this invention heat-forms the laminated board or copper foil which coated copper through a prepreg or a heat resistant film, for example. Can be used when In addition, the release film of this invention can be used, for example in the manufacturing process of a flexible printed circuit board, when bonding a coverlay film or a reinforcement board with a thermosetting adhesive or a thermosetting adhesive sheet by thermocompression molding.

The release film of the present invention is also used for sporting goods such as fishing rods, golf clubs, shafts, and aircraft parts manufactured by curing prepreg containing glass cloth, carbon fiber, or aramid fiber and epoxy resin in an autoclave. It is also useful as a release film at the time of manufacturing a release film, polyurethane foam, a ceramic sheet, an electrical insulation board, etc. at the time of manufacture.

Best Mode for Carrying Out the Invention

Although an Example is given to the following and this invention is demonstrated in more detail, this invention is not limited only to these Examples.

(Example 1)

(1) Preparation of Release Film

Hytrel 2751 (manufactured by Toray DuPont) was used as the resin composition, melt extruded by heating to 250 ° C using an extruder, and extrusion molded from a T-dice to obtain a release film having a thickness of 50 µm.

(2) Production of Resin Film

A low density polyethylene resin (Novtech Polychem Co., Ltd .: Novatec LD LE425) was heated to 230 ° C. in an extruder to be melt plasticized, and extruded from a T-dice to obtain a resin film having a thickness of 100 μm.

(3) Production of copper clad laminate

Using a polyimide film (manufactured by DuPont: Kapton) having a thickness of 25 µm as a base film, a copper-clad laminated sheet bonded with an epoxy-based adhesive layer having a thickness of 20 µm with a copper foil of 35 µm in thickness and 50 µm in thickness on the substrate film Got it.

(4) Production of coverlay film

On the polyimide film (Dupont make: Kapton) of 25 micrometers in thickness, the epoxy adhesive of the flow start temperature of 80 degreeC was apply | coated to thickness of 20 micrometers, and the coverlay film was obtained.

(5) Fabrication of Flexible Printed Boards

The obtained release film, the copper clad laminated board, the coverlay film, the release film, and the resin film were laminated | stacked in this order as one set, 32 sets were installed by heat compression, compression temperature 170 degreeC, compression pressure 3MPa, and compression After thermocompression molding on the conditions for 45 minutes, the compression pressure was released, the resin film was removed, the release film was sealed, and a flexible printed circuit board was obtained.

The coverlay film of the obtained flexible printed circuit board was in full contact with the substrate main body, and the remaining portion of air was not confirmed. The release film was completely peeled also from the electrode part containing the copper foil of the part without a coverlay film, and the copper foil was fully exposed by the electrode part. Moreover, the electroconductivity of the electrode part was enough. Moreover, the runoff of the adhesive agent to the copper foil surface in the part without a coverlay film was 0.1 mm or less from the coverlay film edge part, and the effect of preventing the adhesive agent was also sufficient. Also, no deformation of the circuit was seen at all.

(Example 2)

Except having melt-plasticized at 250 degreeC by the extruder using Hytrel 5557 (made by Toray Dupont) as a resin composition, and extrusion-molding from T-die to manufacture the release film of thickness 50micrometer, and using this, A flexible printed circuit board was prepared in the same manner as in Example 1.

(Example 3)

Example 1 Except having melt-plasticized at 250 degreeC with the extruder using Pelphren S9001 (made by Toyo Bond Co., Ltd.) as a resin composition, and extrusion-molding from T-die to produce the release film of 50 micrometers in thickness, and using this. In the same manner as in the flexible printed board was prepared.

(Example 4)

Example 1 Except having melt-plasticized at 250 degreeC with the extruder at 250 degreeC with the resin composition as a resin composition, and extrude | molding from T-die to manufacture the release film of 50 micrometers in thickness, and using this, Example 1 In the same manner as in the flexible printed board was prepared.

 (Example 5)

Except for using a Nova Duran 5040ZS (manufactured by Mitsubishi Engineering Plastics Co., Ltd.) as a resin composition to melt plasticization at an extruder at 250 ° C., extrusion molding from a T-dice to produce a release film having a thickness of 50 μm, and using the same. A flexible printed circuit board was prepared in the same manner as in Example 1.

(Example 6)

As a resin composition, 70 parts by weight of Nova Duran 5040ZS (manufactured by Mitsubishi Engineering Plastics Co., Ltd.) and 30 parts by weight of Hytrel 7247 (manufactured by Toray DuPont Co., Ltd.) were used, melt-plasticized at 250 ° C. in an extruder, and A flexible printed circuit board was produced in the same manner as in Example 1 except that extrusion molding was performed to produce a release film having a thickness of 50 μm, and the same was used.

(Example 7)

As a resin composition, 70 parts by weight of Nova Duran 5040ZS (manufactured by Mitsubishi Engineering Plastics Co., Ltd.) and 30 parts by weight of pulprene S6001 (manufactured by Toyo Boseki Co., Ltd.) were used, melt-plasticized at 250 ° C in an extruder, and extruded from T-Dice. A flexible printed circuit board was produced in the same manner as in Example 1 except that the molded film was molded to produce a release film having a thickness of 50 µm, and used.

(Example 8)

Using a sealer PT7001 (manufactured by DuPont) as a resin composition, melt plasticizing at 290 ° C. in an extruder, extruding by T-dice, longitudinal stretching twice, and annealing at 230 ° C. to release 50 μm A flexible printed circuit board was produced in the same manner as in Example 1 except that a film was prepared and used.

(Example 9)

A layer having a thickness of 10 µm containing Nova Duran 5040ZS (manufactured by Mitsubishi Engineering Plastics Corporation) using a three-layer coextruder, a layer having a thickness of 30 µm including Hytrel 7247 (manufactured by Toray DuPont), and Nova Duran A flexible printed circuit board was produced in the same manner as in Example 1 except that a release film having a three-layer structure in which a layer having a thickness of 10 µm including 5040ZS (manufactured by Mitsubishi Engineering Plastics Co., Ltd.) was superimposed in this order was used and used. .

(Comparative Example 1)

Using Novatec PP FB3GT (manufactured by Nippon Polychem Co., Ltd.) as a resin composition, melt plasticizing at 250 ° C. in an extruder, extrusion molding from a T-die to prepare a release film having a thickness of 50 μm, and using the same A flexible printed circuit board was prepared in the same manner as in Example 1.

(Comparative Example 2)

A flexible printed circuit board was produced in the same manner as in Example 1 except that Opurene X-88B (manufactured by Mitsui Chemical Industries, Ltd.) containing polymethylpentene having a thickness of 50 µm was used as the release film.

(Comparative Example 3)

100 parts by weight of Hytrel 5557 (manufactured by Toray DuPont) as a thermoplastic resin and 7.7 parts by weight of natural montmorillonite (manufactured by Yojo Co., Ltd., New S-Ben D) subjected to organic treatment with distearyldimethyl quaternary ammonium salt were introduced into the extruder. A flexible printed circuit board was produced in the same manner as in Example 1 except that the film was melt-plasticized at 230 ° C. and extruded from a T-dice to produce a 50 μm thick film.

With respect to the release films produced in Examples 1 to 9 and Comparative Examples 1 to 3, the heat of crystal melting, storage modulus, glass transition temperature, tensile elongation at break, dimensional change rate and out gas generation amount were measured by the following method.

 In addition, in manufacture of the flexible printed circuit board using these release films, peelability, adhesiveness, electrode contamination of the flexible printed circuit board after manufacture, and circuit deformation were confirmed visually and evaluated.

These results and the raw materials and the constitution of each release film are shown in Tables 1 to 4 below.

(Measurement of Crystal Fusion Calorie)

It measured at the temperature increase rate of 5 degree-C / min using the differential scanning calorimeter (DSC 2920 by TA Instruments).

(Measurement of storage modulus)

Using a viscoelastic spectrometer (manufactured by REO-11 Scientific Co., Ltd., RSA-11), the temperature was measured at a temperature increase rate of 5 ° C / min, a frequency of 10 Hz, and a strain of 0.05%. The storage modulus at 23 ° C and 170 ° C was measured. Measured.

(Measurement of glass transition temperature)

Using the viscoelastic spectrometer (manufactured by REO-11 Scientific Co., Ltd., RSA-11) at a temperature increase rate of 5 ° C / min, frequency of 10 Hz, and strain of 0.05%, the maximum of loss tangent (tanδ) obtained is observed. The temperature was made into glass transition temperature.

(Measurement of tensile fracture elongation)

The punching test piece of No. 2 type was measured at 170 degreeC and the test speed of 500 mm / min according to JISK7127.

(Measurement of tear strength)

According to JIS K7128C method, it measured at 23 degreeC and a test speed of 500 mm / min about a rectangular tear test punching piece.

(Measurement of 100% Elongation Load)

The punching test piece of No. 2 type was measured at 170 degreeC and the test speed of 500 mm / min according to JISK7127.

(Measurement of dimension change rate)

On the surface of the release film, the marking lines of 100 mm intervals were written in the direction of extrusion molding (MD direction) and the perpendicular | vertical direction (TD direction) with respect to it, respectively. A release film that was 170 ℃, an average value of was subjected for 60 minutes to a compression load of 3 MPa, measure the distance between the mark, and 32 set _MD L, L _TD. The rate of dimensional change in each direction was computed by the following chemical formula.

% Of dimensional change in MD direction = (L _MD -100) / 100 x 100

Dimensional rate of change (%) in TD direction = (L _TD -100) / 100 x 100

(Measurement of outgas generation amount)

The ATD-400 by a Perkin Elmer company was used as a heat desorption apparatus, and the gas which generate | occur | produced from the film by heating for 10 minutes at 170 degreeC under 25 mL / min of inert gas stream by the dynamic head space method was collected. This was separated using Nippon Denshi Co., Ltd. Automass II-15 which connected the nonpolar capillary column, the toluene conversion amount of the detected peak total area was normalized by the film weight, and this was made into the outgas generation amount.

According to the present invention, it is possible to provide a release film that is excellent in flexibility at high temperatures, conformity to irregularities, heat resistance, mold release property, and non-pollution property, and is easy to discard after use.

Claims (8)

It is a release film used in the manufacturing process of a printed wiring board, a flexible printed wiring board, or a multilayer printed wiring board, At least one surface has a layer which consists of crystalline aromatic polyester which does not contain a diisocyanate component as a matrix, does not contain a layered silicate, and contains the resin composition whose halogen content is 5 weight% or less, The outgas generation amount when the mold release film is heated at 170 degreeC for 10 minutes is 200 ppm or less, The release film characterized by the above-mentioned. delete 2. The release film of claim 1, wherein the crystalline aromatic polyester comprises at least butylene terephthalate as a crystalline component. The release film according to claim 3, wherein the amount of crystal melting heat is 40 J / g or more. The release film according to claim 1, wherein the glass transition temperature of the crystalline aromatic polyester is 0 to 100 ° C. delete delete delete